Sander drum



Aug. 15, 1933. R. A. WlLLIAMS SANDER DRUM Filed Oct. 8, 1928 2 Sheets-Sheet 1 Aug. 15, 1933. R. A. WILLIAMS 1,922,905

' SANDER DRUM Filed Oct. 8, ,1928 2 Sheets-Sheet 2 Patented Aug. 15, 1933 UNITED STATES PATENT OFFICE Yates-American Machine Company, Beloit,

Wis., a Corporation of Delaware Application October 8, 1928. Serial No. 311,000

8 Claims.

The. present invention pertains to sander drums of the type in which the covering of sand paper or other abrasive material is wound spira1- 1y on the drum.

. The object of the invention is to provide improved means in connection with such a drum for taking up the slack which develops in the covering.

While the foregoing statement is indicative in a general way of the nature of the invention, other objects and advantages will be evident to those skilled in the art upon a full understanding of the construction, arrangement and operation of the improved slack take-up device.

In order that the invention may be readily understood, two difierent forms of the same are presented herein, but it will of course be appreciatedthat the invention is susceptible of embodiment in other structurally modified forms coming equally within the scope of the claims.

In the accompanying drawings: Fig. 1 is a sectional view through a sander drum equipped with the slack take-up device of the invention, showing the device in the position which it assumes when the covering is being applied to the drum;

Fig. 2 is an end view of the drum;

Fig. 3 is a fragmentary sectional view through the drum, corresponding to Fig. 1, showing the device in the position which it assumes after the covering has been applied to the drum and a certain amount of slack has been taken up;

Fig. 4 is a perspective view of a spacing member used in holding the head of the drum up against the body of the drum while the covering is being wound about the body and attached to the head;

Fig. 5 is a fragmentary sectional view through a drum equipped with a modified form of the slack take-up device, showing the device in the position which it assumes when the covering is being applied; and

Fig. 6 is a fragmentary sectional view through 5 the drum illustrated in Fig. 5, showing the device in the position which it assumes after the covering has been applied to the drum and a certain amount of slack has been taken up.

The form of the invention illustrated in Figs. 1 to 4 inclusive will first be described. The sander drum shown therein consists of a cylindrical body 10 which is made up of one or more sections and is mounted on a shaft 11. A head 12 is fixedly secured to one end of the body 10, and another head 13 is movably associated with the other end of the body. The head 13 is journaled on the of a spacing member 26 of any suitable description which is inserted between the head and an shaft 11 and is provided with obliquely slotted ears 14 which extend into the end of the body 10 and coact with pins 15 which project inwardly from the body into the slots in the ears 14, causing the head 13 to be limited to a spiral movement with respect to the body. A covering 16 of sand paper or other abrasive material is adapted to be clamped at one end by a band 17 about the periphery of the fixed head 12, then wound spirally about the body 10 upon a pad 18, 5 and then clamped at the other end by a band 19 about the periphery. of the spirally movable head 13.

A plate 20 is mounted within the body 10 adjacent the head 13, and a number of coil springs 0 21 are arranged obliquely between the plate and. the head about bolts 22 which are screwed into threaded apertures in the head and extend loosely through apertures in the plate. The springs 21 tend to move the head 13 spirally away from the end of the body 10 after the covering 16 has been applied, whereby to take up the slack which develops in the covering, and the heads on the bolts 22 prevent the head 13 from moving too far in that direction.

In applying the covering to the drum, the head 13 is forced in toward the end of the drum 10 against the yielding resistance of the springs 21 by means of a lever 23 of any suitable description which fulcrums at 24 against an adjacent bearing bracket and bears at 25 against the head. When the head 13 reaches the position shown in Fig.1, it is held against return movement under the action of the compressed springs 21 by means adjacent collar 27 on the shaft 11. As soon as the spacing member 26 has been properly placed, the lever 23 may be removed. After the covering has been spirally wound on the drum and clamped to the periphery of the head 13 by the band 19, the pressure on the spacing member 26 may be temporarily relieved by use of the lever 23 again to permit removal of the spacing member. The springs 21 will then tend to move the head 13 spirally, and the covering 16 attached to the head will be drawn taut. The springs 21 will prevent any slackness from developing in the covering, since they will move the head 13 spirally to comr pensate for any stretching in the covering.

In the form of the invention disclosed in Figs. 5 and 6, the lever 23 and spacing member 26 are dispensed with and the means employed in lieu thereof for holding the spirally movable head 28 in its innermost position against the action of the springs 29 consists of threaded bolts 30 which are anchored in obliquely offset portions of the plate 31 and project loosely through apertures in obliquely offset portions of the head 28. The bolts 30 form guides for the springs 29 and are screw-threaded at their outer ends to receive nuts 32. When the covering is to be applied to the cylinder,. the nuts 32 are drawn up on the bolts to draw the head 28 up against the end of the body 33, and, after the covering has been attached to the periphery of the head 28, the nuts 32 are backed off on the bolts 30 to the position shown in Fig. 6, where they are locked in position by means of cotter pins 34 and serve to limit the spiral movement of the head relative to the body.

I claim:

1. In a device of the character described, a drum body on which a covering of abrasive material is adapted to be spirally wound, a spirally movable drum head at one end of the body to which one end of the covering is adapted to be attached when the head is in its initial position nearest the end of the body, means tending to move the head spirally away from its initial position to tighten the covering, and means for holding the head in its initial position against the action of said first mentioned means, said last mentioned means being released after the covering has been attached to permit said first mentioned means to tighten the covering.

2. In a device of the character described, a drum body on which a covering of abrasive material is adapted to be spirally wound, a spirally movable drum head at one end of the body to which one end of the covering is adapted to be attached when the head is in its initial position nearest the end of the body, and obliquely extending coil springs compressed between the head and the body when the head is in said initial position for moving the headspirally away from its initial position.

3. In a device of the character described, a drum body on which a covering of abrasive material is adapted to be spirally wound, a spirally movable drum head at one end of the body to which one end of the covering is adapted to be attached when the head is in its initial position nearest the end of the body, compressed coil springs acting on the head to move the same spirally away from its initial position, and means for holding the head in its initial position against the action of said springs.

4. In a device of the character described, a drum body on which a covering of abrasive material is adapted to be spirally wound, a spirally movable drum head at one end of the body to which one end of the covering is adapted to be attached when the head is in its initial position nearest the end of the body, means tending to move the head spirally away from its initial position, means for holding the head in its initial position against the action of such first mentioned means, and means for movingthe head into its initial position against the yielding resistance of said first mentioned means.

5. In a device of the character described, a drum body on which a covering of abrasive material is adapted to be spirally wound, a spirally movable drum head at one end of the body to which one end of the covering is adapted to be attached when the head is in its initial position nearest the end of the body, a plate fastened in the end of the body adjacent the head, guide rods extending obliquely between the plate and the head, and compressed coil springs mounted on the guide rods for moving the head spirally away from its initial position.

6. In a sander drum, a cylindrical body, a fixed head at one end of the body to which one end of a spirally wound covering on the body is adapted to be attached, a spirally movable head at the other end of the body to which the other end of the covering is adapted to be attached, springs tending to move the last mentioned head spirally away from the body, and means for holding the springs compressed to prevent operation of the same while the covering is being attached to the spirally movable head.

l. In a sander drum, a cylindrical body, a fixed head at one end of the body to which one end of a spirally wound covering on the body is adapted to be attached, a spirally movable head at the other end of the body to which the other end of the covering is adapted to be attached, springs tending to move the last mentioned head spirally away from the body, and means for compressing the springs to prevent operation of the same while the covering is being attached to the spirally movable head. 1

8. In a device of the character described, a drum body on which a covering of abrasive material is adapted to be spirally wound, a spirally movable drum head at one end of the body to which one end of the covering is adapted to be attached when the head is in its initial position nearest the end of the body, springs for moving the head spirally away from its initial position to tighten the covering, and readily releasable means for holding the head in its initial position against the action of said springs,

RICHARD A. WILLIAMS. 

